Which of the following is NOT a typical duty of a security guard?

Conducting private investigations is not a typical duty of a security guard. Security guards are primarily tasked with maintaining safety and security within specific premises, which includes monitoring surveillance equipment, patrolling areas, and responding to incidents such as disturbances, thefts, or emergencies. These responsibilities ensure a secure environment and often involve adhering to established security protocols.

In contrast, private investigations involve a more specialized skill set and legal authority, usually performed by licensed private investigators. This might include gathering evidence, interviewing witnesses, or conducting surveillance for investigations that don't fall under the routine duties of security personnel. Therefore, while both roles play important parts in safety and security, the activities of a security guard are generally focused on immediate safety and compliance rather than the nuanced and detailed processes involved in private investigations.